#editor {
    position: absolute;
    top: 15%;
    right: 0;
    bottom: 0;
    left: 0;
    }
#btn-save {
    position: relative;
    overflow: hidden;
    margin: 10px;
    left: 100%;
    
    }
#btn-back {
    position: relative;
    overflow: hidden;
    margin: 10px;
    left: 70%;
    }